The present invention relates to photographic or motion picture cameras which have an exposure control apparatus which is properly operable only when the energizing voltage applied thereto has an amplitude which is somewhere in the range between a predetermined minimum amplitude and a predetermined maximum amplitude. These cameras include batteries whose output voltage is subject to undesired decreases.
In photographic and motion picture cameras the mechanical control and regulating arrangements are being replaced by electronic circuits on a larger and larger scale. Such exposure control circuits operate adequately only when the energizing voltage applied thereto exceeds a predetermined minimum amplitude and is less than a predetermined maximum amplitude. However the output voltages of the battery tend to decreases during its lifetime. Even for a new battery, the output voltage may decrease considerably under load particularly when the temperature is low. Exposure control circuits and in particular such circuits utilizing MOS components thus may not operate properly when the energizing voltage applied thereto is a directly applied battery output voltage.